write
Writes a long to this sink in signed decimal form (i.e., as a string in base 10).
Buffer buffer = new Buffer();
buffer.writeDecimalLong(8675309L);
buffer.writeByte(' ');
buffer.writeDecimalLong(-123L);
buffer.writeByte(' ');
buffer.writeDecimalLong(1L);
assertEquals("8675309 -123 1", buffer.readUtf8());